1. Field of the Invention
This invention relates to a physiologically balanced, ionized, acidic solution that is useful in wound healing and other applications in which antimicrobial properties are desirable. The ionized solution may be prepared by electrolysis, i.e., it is an electrolyzed solution or by other methods including chemical or physical methods. The solution may also be prepared in situ. In addition, the invention relates to a methodology of using the solution of the invention, in a variety of applications, for example, a specialized bandage which may be used in combination with the solution or with other solutions or topically applied materials.
2. Brief Description of the Background Art
Various electrolyzed acidic salt solutions, their properties, and their uses have been described in the art. Several examples are provided below.
U.S. Pat. No. 5,622,848, issued Apr. 22, 1997, to Morrow, discloses a microbicidal solution for in vivo and in vitro treatment of microbial infections. The solution comprises an electrolyzed saline containing regulated amounts of ozone and active chlorine species, wherein the ozone content is between about 5 and 100 mg/L, the active chlorine species content is between about 5 and 300 ppm and a pH range from 7.2-7.6. The active chlorine species comprises free chlorine, hypochlorous acid, and the hypochlorite ion, as measured by a chlorine selective electrode. The solution is prepared by subjecting a 1% or less saline solution to electrolysis under conditions sufficient to produce the desired active ingredients. The solution is preferably utilized at an isotonic saline concentration, and may be adjusted with hypertonic saline. The solution may be used for in vitro treatment of infected whole blood, blood cells, or plasma to reduce contamination, and may be used in the treatment of fluids infected with HIV, hepatitis, and other viral, bacterial, and fungal agents. The solution may also be administered to warm-blooded animals, including humans, by intravenous injection or other modes, for similar purposes.
PCT publication No. WO9934652, published Jul. 8, 1999, of Marais, discloses the use of an electrochemically activated sodium hypochlorite-free irrigating medium to reduce the proliferation of bacteria and other microorganisms during tooth root canal. Anion- and cation-containing solutions are obtained by electrolysis of a 10% aqueous NaCl solution. The anion-containing solution is used at a pH of about 2-7 and an oxidation reduction potential (ORP) of about +1170 mV; the cation-containing solution is used at a pH of about 7-13 and an ORP of about −980 mV.
X. W. Li et al. (Chinese J. Epidem., 17(2), pp. 95-98, 1996) reported a preliminary study of the microbicidal effect of electrolyzed oxidizing water. Electrolyzed oxidizing water was shown to completely kill Staphylococcus aureus and Escherichia coli within 15 seconds, while 10 minutes were required to completely kill all spores of Bacillus subtilus var. niger. Thirty seconds were needed to destroy the antigenicity of HBsAg. The oxidation reduction potential and pH values of electrolyzed oxidizing water were not significantly changed when stored for three weeks at room temperature under air-tight, light-free conditions.
A. Iwasawa et at. (J. Jap. Assoc. Infec. Diseases, 70(9), pp. 915-922, 1996) evaluated the bactericidal effect of acidic electrolyzed water on S. aureus, S. epidermidis, and Pseudomonas aeruginosa. At pH 5.0 to approximately 6.0, three bacterial strains were killed soon after being exposed to the acidic water containing 50 mg/L chloride, and the chloride concentration reportedly did not change after standing open for 6 hours. At pH 2.67 to approximately 2.80, the bactericidal effects were observed at a chloride concentration of 5 mg/L, and 80% of the chloride reportedly remained after standing open for 6 hours.
H. Tanaka et al. (J. Hosp. Infect., 34(1), pp. 43-49, 1996) reported on the antimicrobial activity of superoxidized water. Superoxidized water is described as “a strong acidic and colorless solution with a high oxidation-reduction potential. The solution having an active chlorine concentration of 30 ppm, is prepared by mixing a small amount of salt with tap water in an electrolyser”. The antimicrobial activity of superoxidized water was tested against methicillin-sensitive S. aureus, Serratia marcescens, E. coli, P. aeruginosa, and Burkholderia cepacia. The number of bacteria was reduced below the detection limit following incubation in superoxidized water for 10 seconds. The bactericidal activity of superoxidized water was similar to that of 80% ethanol, but superior to that of 0.1% chlorhexidine and 0.02% povidone iodine.
Y. Inoue et al. (Artificial Organs, 21(1), pp. 28-31, 1997) reported on the use of electrolyzed strong acid aqueous solution lavage in the treatment of peritonitis and intraperitoneal abscess. Peritoneal and abscess lavages were performed using an electrolyzed strong acid aqueous solution to treat seven patients with peritonitis and intraperitoneal abscesses. The period of irrigation in the seven patients ranged from 9 to 12 days, with conversion to microorganism negative state observed within 3 to 7 days. The authors describe the solution as being “acidic water that contains active oxygen and active chlorine and possesses a redox potential” and having an active chlorine concentration less than 50 ppm.
S. Sekiya et al. (Artificial Organs. 21(1), pp. 32-38, 1997) reported on the use of electrolyzed strong acid solutions in the treatment of infectious skin defects and ulcers using. The clinically applied therapy of electrolyzed strong acid aqueous solutions were found to be effective in the treatment of infectious ulcers. Sekiya et al. describe the strong aqueous solution (ESAAS) as being “generated by electrolyzing water and a small quantity of salt with a cation transfer filter.”
H. Hayashi et al. (Artificial Organs, 21(1), pp. 39-42, 1997) reported on the use of electrolyzed strong acid aqueous solutions (ESAAS) in the treatment of mediastinitis following cardiovascular surgery. Hayashi et al. described ESMS as being “produced by electrolyzing sodium chloride solution. ( . . . ) ESAAS is produced by electrolyzing the sodium chloride solution using an ion-exchange membrane that separates the positive and negative electrodes. A small amount of sodium chloride is added to the water to facilitate electrolysis and increase the concentration of dissolved chloride.” The solution is disclosed as having a pH less than 2.7, Cl2 more than 30 ppm, ORP more than 1100, and dissolved O2 of more than 20 ppm. The mediastinal wound was left open and irrigated with ESMS one to three times daily until the infection was eradicated. Satisfactory growth of granulation tissue was observed in all patients treated, with no evidence of adverse effects attributable to ESMS.
N. Tanaka et al. (Artificial Organs, 23(4), pp. 303-309, April 1999) reported on the use of electrolyzed strong acid aqueous solutions to clean and disinfect hemodialysis equipment. The solutions were found to directly inactivate bacterial endotoxins, and proved to be more economical than the conventional disinfecting method. The “electrolyzed strong acid aqueous solutions are disclosed to be “strongly acidic water which is made by electrolyzing tap water containing 500-1000 ppm salt (NaCl >99% pure) in a cell partitioned by a polyester diaphragm. It has an acidity of 2.3-2.7 pH, more than 1,000 mV in oxidation-reduction potential and 10-50 ppm in available chlorine.”
J. B. Selkon et al. (J. Hosp. Infec., 41(1), pp. 59-70, January 1999) evaluated the antimicrobial activity of a new superoxidized water, STERILOX® (Sterilox Medical Limited, 85 E Milton Park, Abingdon, Oxon OX14 4RY, UK) for the disinfection of endoscopes. This superoxidized water is prepared from a 35.7% NaCl in a 1 to 20 dilution, and is described as being “generated at the point of use by passing a saline solution over coated titanium electrodes at 9 amps. The product generated has a pH of 5.0-6.5 and an oxidation reduction potential of >950 mV.” The antimicrobial activity of STERILOX® was tested against Mycobacterium tuberculosis, M. avium-intracellulare, M. chelonae, E. coli (including type 0157), Enterococcus faecalis, P. aeruginosa, B. subtilus var. niger spores, methicillin-resistant S. aureus, Candida albicans, poliovirus type 2, and human immunodeficiency virus HIV-1. Under clean conditions, freshly generated STERILOX® was found to be highly active against all these microorganisms, giving a 5 log10 (99.999%) or greater reduction in 2 minutes or less.
U.S. Pat. No. 6,296,744 assigned to Sterilox Technologies International Limited, discloses an apparatus for the electrochemical treatment of a liquid medium, which allows for the production of a sterilizing solution as well as the decontamination and purification of liquid mediums from toxic organic substances and other impurities. The process utilizes solution having an average salinity of 0.1 to 1.0 g/l and a chloride concentration of up to 50 mg/l, and the process is carried out using a current of 500 to 1000 mA with potential difference of 10-12 volts. The patent also discloses that the optimum pH parameters for anodically-treated water are 6-7, and for cathodically-treated water 8-9. However, the patent further discloses that the apparatus proposed aims to achieve solutions of active chlorine with a pH of between 4.5 and 7.5 used as a sterilizing solution, disinfectant, decontaminant, bleaching agent, detergent or medicine with antibacterial and antiviral action.
K. S. Venkitanarayanan et al. (Appl. & Env. Microbiol., 65(9), pp. 4276-4279, September 1999) evaluated the efficacy of electrolyzed oxidizing water for inactivating E. coli 01 57:H7, Salmonella enteritidis, and Listelia monocytogenes. A five-strain mixture of E. coli 01 57:H7, S. enteritidis, or L. monocytogenes was inoculated in electrolyzed oxidizing water at various temperatures, for various time periods. The electrolyzed oxidizing water is produced from a saline base solution containing approximately 12% by weight. NaCl. The electrolyzed oxidizing water is also described as having a 0.1% salt, Cl2 of 10-80 ppm, pH less than 2.7 as well as an electrolyzed oxidizing water having Cl2 of 73-86 ppm, and pH of 2.38-2.48. At 4° C. and 23° C., an exposure time of 5 minutes, the population of all three pathogens in the treatment samples was reported to be reduced by approximately 7 log CFU/mL, with compete inactivation by 10 minutes of exposure. A reduction of greater than 7 log CFU/mL in the levels of the three pathogens was reported to occur in the treatment samples incubated for 1 minute at 45° C. or for 2 minutes at 35° C.